 /*******************************************************************************
  * Copyright (c) 2004, 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.runtime.content;

 import java.io.IOException ;
 import java.io.Reader ;

 /**
  * Text content describers extend basic content describers to provide
  * the ability of scanning character streams (readers). Describers for
  * text-based content types must implement this interface
  * instead of <code>IContentDescription</code>.
  * <p>
  * Note: It is expected that content describer implementations be declared in a package
  * that is exempt from plug-in activation (using the Eclipse-AutoStart bundle
  * manifest header). Since all describers are instantiated when the content type
  * framework is initialized, failure in complying with this requirement causes
  * premature activation, which must be avoided. Future implementations of the
  * framework might refuse to instantiate describers if doing so would trigger
  * activation of the corresponding plug-in.
  * </p>
  * <p>
  * Clients may implement this interface.
  * </p>
  *
  * @see IContentDescription
  * @since 3.0
  */
 public interface ITextContentDescriber extends IContentDescriber {
     /**
      * Tries to fill a description for the given contents. Returns
      * an <code>int</code> indicating whether the given stream of
      * characters represents a valid sample for this describer's corresponding
      * content type. If no content description is provided, this method should
      * only perform content type validation.
      * <p>
      * The stream provided must be kept open, and any IOExceptions while
      * reading it should flow to the caller.
      * </p>
      *
      * @param contents the contents to be examined
      * @param description a description to be filled in, or <code>null</code> if
      * only content type validation is to be performed
      * @return one of the following:<ul>
      * <li><code>VALID</code></li>
      * <li><code>INVALID</code></li>
      * <li><code>INDETERMINATE</code></li>
      * </ul>
      * @throws IOException if an I/O error occurs
      * @see IContentDescription
      * @see #VALID
      * @see #INVALID
      * @see #INDETERMINATE
      */
     public int describe(Reader contents, IContentDescription description) throws IOException ;
 }

